Justinlp

I got one main phone line and three rings on it.. One ring is the default and two extras for other people to know its for them. How can i set my IVM to only answer the calls from my ring only not the default of the 3rd ring? How do i find out what the MS of my ring is and where do i need to put this information in at to make it work. My ring is (Short. Long. Short)... thanks